Performance, carcass, and pork traits in barrows and gilts slaughtered over 130 kg: insights from a Brazilian perspective.

Abstract

Brazil is a major pork producer, with increasing market demands driving heavier slaughter weights. Sexual condition is a well stablished factor influencing pig performance, carcass composition, and pork quality, with previous studies focusing primarily on lighter pigs. This study compared the performance, carcass characteristics, and pork traits of heavy-slaughtered barrows and gilts. A total of 144 pigs (72 barrows; 72 gilts), with an average weight of 55.68 ± 6.48 kg, were utilized in a randomized complete block design. They were allocated into 48 pens based on sex and body weight. Each pen (three pigs of the same sex) was considered the experimental unit for performance evaluation across the growing, finishing 1, and finishing 2 phases, with ad libitum access to water and feed. After a 63-d trial, one pig per pen (n = 48; 24 barrows, 24 gilts) was slaughtered for carcass and pork trait analysis. Data analysis was conducted using SAS (SAS Institute Inc., Cary, NC), and the effects of sexual condition were analyzed by ANOVA. Data were presented as least squares means, with differences deemed statistically significant at P < 0.05. Throughout the study, barrows exhibited higher average daily gain (1.306 vs. 1.206 kg, + 8.25%, P = 0.0004) and feed intake (3.378 vs. 2.957 kg, + 14.24%, P < 0.0001), while gilts showed superior feed efficiency (0.409 vs. 0.387, + 5.74%, P = 0.009). However no final weight was observed between barrows and gilts at the end of the trial, where they achieve 153 days of age (P > 0.05). Although hot and chilled carcass weights did not differ (P > 0.05), gilts had greater hot carcass yield (+ 2.83%) and chilled carcass yield (+ 3.08%) than barrows (P < 0.0001). Gilts also exhibited lower initial pH (-3.28%, P = 0.006) and initial temperature (-4.46%, P = 0.01), with no differences in final temperature. No differences were found in L* and a* color indices, but gilts had lower b* (-3.98%, P = 0.004) and Chroma (-4.06%, P = 0.008) values compared to barrows. These results suggest that increasing slaughter weight above 130 kg leads to minimal practical differences between barrows and gilts in performance, carcass traits, and pork quality, reinforcing the suitability of both sexes for heavier slaughter weights in Brazilian production systems.